Pop-ups have fairly recently become frequently used in advertising and in other promotional endeavors, whereas they had been used in the greeting card field and in children's books for a number of years. Such pop-up pieces have become generally available to the advertising field as a result of the developments shown in several earlier patents, particularly U.S. Pat. No. 3,995,388, issued Dec. 7, 1976, which discloses methods for making pop-up paper products having significant advantages over hand-assembly methods that had been generally theretofore employed. U.S. Pat. No. 4,146,983, issued Apr. 3, 1979, discloses other methods for making novel promotional items, particularly those which are designed to present a plurality of coupons or the like to a recipient upon the opening of a folder. U.S. Pat. No. 4,337,589 discloses manufacturing techniques, specifically suited for mass production on a web-press or the like, for making pop-up advertising pieces and the like, the details of the disclosure of which are incorporated herein by reference.
The foregoing patents describe different manufacturing techniques useful for making advertising and promotional pop-ups such as these have been frequently used to create impact and enjoyment in books, in greeting cards and in advertising inserts. The foregoing advances in designs and in manufacturing methods have enabled volume production of such products at significant cost savings and thus have increased their use.
A general characteristic of such pop-ups is the movement of the pop-up element from a flat, substantially single plane into a three-dimensional orientation upon the opening of a pair of cover pieces or basepieces, generally in the form of a folder inside which the pop-up is located. By attaching the pop-up elements to opposite panels of the basepieces, for example, along angles created by lines of weakness, such as score lines and/or perforations, in combination with adhesive bonds, pressure or stress points are created which, upon opening of one cover, cause the pop-up to be erected. However, the pressure or stress which is created upon opening is sufficient so that, when the cover is manually released, it will draw the cover either partially or entirely closed.
Although a pair of basepieces have heretofore been utilized in such pop-up units, it has not been found that improved pop-up designs are feasible that eliminate one or more of the basepieces, as are methods for mass production of such improved designs.